Stephen d



(Nd-Model.) 9 i S. D. FIELD.

UNISON MECHANISM FOR PRINTING TELEGRAPHS.

Pa-tented Feb. 19, 1884.

NrTEn STATES PATENT UEETCE.

STEPHEN 1). FIELD, oENEW YORK, N. Y.

UNISON MECHANISM FOR PRlNTlNG-TELEGRAPHS.

SPECIFICATION forming part of Letters Patent No. 298,959, dated February 19, 188 1.

Application filed January 14, 1884. (N0 model.)

known as the unison mechanism in step by-step printing-telegraphs; and it consists in a novel combination and arrangement of devices in ,the transmitter and the receivers,

so that the conjoint action of both is necessary to permit the continuity of action of both classes of instruments, the unison devices being automatically brought into or out of action without any care or attention on the part of the operator, and without any cessation of the normal operations of the instruments, eX- cepting such as may be necessitated by a failure of unison inthe type-wheels, and to bring them to unison.

The means of accomplishing this is more fully hereinafter set forth and claimed.

A two-wire printer is used, one circuit c011- trolling the type-wheel escapement and mechanism by means of alternating currents, while the other controls the press or printing mechanism in any well-known manner. A transmitter is used having a rotating arm adapted to be stopped by the depression of a pin in its path, the arm being attached to the shaft of an anchor controlling an escapement which operates the currentsending device, which may be arranged to send reversed currents or pulsations of one polarity only. In the typewheel'circuit is placed, at the transmitter, a magnet having an armature-lever whose free end is formed into a hook or otherwise arranged so as be adapted, when the armaturelever is not attracted by the magnet, to catch and stop the lever arm or finger of the transmitter. At the receiver another magnet is placed in the same circuit, having an arma ture-lever whose free end is formed into a hook or otherwise arranged so as to be adapted to catch and hold a finger or arm projecting from the type-wheel shaft or some member of the type-wheel train. Inboth these magnets the magnetic strength and the resilience of the retractors of the armature-levers are so adcient to so magnetize the magnets as to cause them to attract their armatures. The consequence is that both the armature-levers remain away from their magnets during the ordinary working of-the transmitter, and in such position catch and hold the arms or levers both in the transmitter and receiver. Then, however, the arm in the transmitter is so caught and held, a prolonged current is sent over the lines, passing through both magnets and causing them to attract their armatures and release the arms or levers. It follows, then, that in every revolution both must be in unison to be simultaneously released and allowed to proceed, so that if eitherhas been moving too fast or too slow one or the other will be held till both are at the same point, where both are released and allowed to proceed from the same initial point. By such an arrangement unison may be automatically secured without increase of battery, the shunting of resistance, or special operation therefor, as has hitherto been practiced.

Sui-table arrangements for carrying this invention into eficct are shown in the drawings, wherein is represented, mainly diagrammatically, the transmitting and receiving stations and instruments, T at the left being the transmitting-station, and R at the right the receiving-station, connected by an escapement or type-wheel circuit, 4, of any desired length.

It is to be understood that any number of receiving-stations B may be connected in the circuit or line 4. l n

The transmitter is primarily of the ordinary construction,having an escape-wheel, B, driven by any suitably prime motor, (n ot here shown,) and actuating the anchor A, and thereby controlling the springs R R and their contact with 'a common anvil, B, so as to connect the battery M B to line and ground alternately and as clearly shown in the drawings.

Attached to the shaft of B is the finger-arn1 0, arranged to be stopped by the depression of any of the keys D, in the well-known manner.

magnet E, having an armature-lever, F, provided with the usual retractor and contactstops. The end of the lever F is fashioned into a hook, a, and the whole is so arranged that the arm or'finger 0 shall be caught by In the line-circuit 4c is placed the electro- IOO a, when the armature-lever is held from the I magnet by the spring 8. The receiving-instrument R is conventionally represented by the polarized magnet H, actuating the armature, and escapement a, controlling the movement of the escape-wheel f on the shaft of the typewheel (I, the printing and inking mechanism, paperfeed, framing, and other details not necessary to the showing of the invention being omitted.

In the escapementcircuit 4 at the receiver is placed the magnet I, having an armature-lever, h, provided with the usual stops and retractor.- The end of the armature-lever h is so placed, or it is formed into the hook i, as to catch and hold an arm or finger, g, projecting from the typewheel shaft or from some member of the type-wheel train, and thereby stop the rotation thereof when the lever h is held away from the magnet by the spring 8. The magnetic force of G and I and the retractile force of their springs s s are so adjusted relatively that the short or ordinary impulses of alternating polarity thrown through them when the transmitter is working normally are not sufficient to charge them to the degree necessary to attract their armatures. The arma ture levers therefore normally stand away from their magnets, as shown, and in position to stop both transmitter and receiver once during every revolution. As O is rotated by the motor of the transmitter it proceeds uninterruptedly until it reaches a, when it is stopped. This stoppage causes a prolongation of the current or impulse last transmitted until E is sufficiently charged to overcome the stress of s, attracting the armature and releasing O. This same prolongation has a similar effect on I, causing it to attract h and release 9. By these means a perfect unison between the transmitter and all receiversin circuit is automatically secured without care or attention on the part of the operator and without stoppage of the instrument for its normal work, excepting the slight stoppage of O, which generally is so momentary as practically not to be observable. The magnets Gare shown in a relay for controlling the second or printing circuit, 5, it being controlled by a local battery, L B, and local circuit 6, one terminal of which is con nected to the arm or lever O and the other to the keys D D, so that it is completed on contact of C and. any D on the'depression of the latter to stop 0.

I do not here claim, broadly, controlling the unison mechanism of a receiver by prolonged impulses automatically transmitted at definite intervals, inasmuch as this feature has been made by me the subject of a separate application for Letters Patent.

Having described my invention, what I claim, and desire to secure by Letters Patent,

1. In a printing-telegraph, the combination, with a receiver, a unison mechanism therefor, and means for controlling said mechanism. by a prolongation of current, of a transmitter and means for automatically halting the same at definite intervals to prolong the pulsations or impulses upon the line, substantially as and for the purposes hereinbefore set forth.

2. In aprinting-telegraph, the combination, with the transmitter and escapement or type wheel circuit, of a magnet at the transmitter and a magnet at the receiver, both adjusted to respond only to prolonged pulsations, and controlling the unison mechanism by their conjoint action, substantially as set forth.

3. In a printing-telegraph system, the combination ofa main battery, a transmitter adapted to send short or normal pulsations there from through the type-wheel or escapementcircuit, and means for halting or stopping the transmitter at definite intervals to transmit an abnormal or prolonged pulsation, substantially as set forth.

4. In a printing-telegraph system, the combination of one main line automatically controlled by the transmitter, and controlling in turn the printing mechanism, a second main line controlling the escapement or type-wheel mechanism, and independent magnets in the latter, adapted to arrest both the transmitting and receiving mechanism at definite intervals, and to release both upon a prolonged or abnormal current, substantially as set forth.

In testimony whereof I have hereunto set my hand this 11th day of January, 1884:.

. STEPHEN D. FIELD.

W'itnesses:

LUTHER E. SHTNN, Gno. W. CASPER. 

